" Obviously consumption-goods, taken as a whole, have in this sense the longest period of production, since of every productive process they constitute the last stage. Thus if the first impulse towards the increase in effective demand comes from an increase in consumption, the initial elasticity of employment will be further below its eventual equilibrium-level than if the impulse comes from an increase in investment. Moreover, "

― John Maynard Keynes , The General Theory of Employment, Interest, and Money